Control system



AQH. CANDEE AND H. H. JOHNSTON.

CONTROL SYSTEM. APPLICATION Huzu' AUG-7,1916.

1 $381,277. Patented June 14, 1921.,

Z SHEETS-SHEET I. t 02E EH4 Al F/ WITNESSES 1 lNVENTOR Andrew H. [ans/eag in A. H. CANDEE AND H. H. JOHNSTON. 00 111101 SYSTEM. APPLICATIONFILED AUG-7. 1916.

1,381,277. PatentedJune 14,1921.

2 SHEETSSHEET 2.

UNITED sures PATENT OFFICZE.

ANDFIEW H. GANDEE, OF PITTSBURGH,

AND HARVEY H. JOHNSTON, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRICAND OF EDG-EWOOD, MANUFACTUR- ING- COMPANY, A CORPORATION OF PENNSYLVANIA.

CONTROL SYSTEM.

Specification of Letters Patent.

Application filed August 7, 1916. Serial No. 113,481.

To all whom it may concern Be it known that we, ANDREW H. Simon, 7

a citizen of the United States, and a resident of Pittsburgh, in thecounty of Allegheny and State of Pennsylvania, and HARVEY H. JOHNSTON, acitizen of the United States, and a resident of Edgewood, in the countyof Allegheny and State of Pennsylvania, have invented a new and use fulImprovement in Control. Systems of which the following is aspecification.

Our invention relates to systems of control for-electric vehicles andparticularly to systems wherein the motors are adapted to be, connectedto a supply circuit in series and in parallel-circuit relation.

One object of our invention is to provide a system of the aboveindicated class that shall effect the transition of the motors fromseries to parallel-circuit relation with a minimum number of switchesand with substantially no decrease in the torque supplied by the motors.

Another object of our invention is to provide a system wherein thetransition of the motors from series toparallel-circuit relation may beeffected with a, minimum amount of arcing at the switches and whereinthe current flow through one of the motors is reversed.

A further object of our invention is to provide a system having anumberof resistors and circuit connections so disposed that themotors may beaccelerated by a minimum number of. switches.

More specifically, our-invention consists of a control system providedwith three motors initially connectedin series with a number ofresistors to a supply circuit. A minimum number of switches is providedfor ex cluding the resistors in sequence from the motor circuit and forplacing the resistors in parallel in the motor circuit, and two switchesare provided for. effecting the transitionof the motors from series toparallel-circuit relation.-

.In the accompanying. drawings illustrate.

ing our 'inventiornFigure 1 is a diagrammatic view of a control systemconstructed inaccordance with our invention; Fig. .2 1s

a diagrammatic view of the control circuits for governing the operationof the switches shown in Fig.1; Fig.3 is a control chart disclosing the,sequence of operation of the switches shown in Fig. 1; Figs. 4, 5, 5, 6and are diagrammatic views illustrating the circuits formed through themotors shown in Fig. 1; Fig. 8 is a diagrammatic View of a modificationof our invention; Fig. 9 is a diagrammatic View of thecontrol circuitsfor governing the operation of the switches disclosed in Fig. 8; Fig. 10is a control chart disclosing the sequence of operation of the switchesin Fig. 8, and Figs. 11 to 19, inclusive, are diagrammatic views of thecircuits formed through the motors shown in FilgN. 8. e

eferring to Fig. 1 of the drawings, mo-

tors 1, 2 and 3, respectively comprising armatures A1, A2 and A3 andfield windings F1, F2 and F3, are adapted to be connected in series withresistors T1 and r2 across a supply circuit comprising a trolleyconductor 23 and a ground conductor 9 and to be controlled by means ofunit switches R1 to R4, inclusive, and P, S and G. a

Referring to F i .2 of the drawings, a master controller C, having amovable contact segment 4, is adapted to be moved through positions 1 to7, inclusive, to engage contact fingers 5 to 12, inclusive, and

complete circuits from a batteiiy B through the coils of the switches R1to and S, P and G. r

In Fig. 8 of the drawings, three motors 14, 15 and 16, respectivelycomprising armatures A4, A5 and A6 and field windings F4, F5 and F6, areadapted to be connected, with resistors r3, T4 and 15, across a supplycircuit comprising a trolley conductor t1 and a ground conductor 91 andto be controlled by means of the unit switches R5 to R8, inclusive, andS1, P1 the drawings, a master controller M61, having a movable contactsegment 17, is adapted to engage stationary contact fingers 18 to 25,inclusive, when moved through positions 1 to 10, inclusive, and completecircuits from a battery Bl through the coils of the switches R5 P1 andG1.

The operation of the system disclosed in Figs. 1 to 7 ,inclusive, whenthe master controller is moved through positions 1 to 7, inclusive, isas follows. controller MO is moved to position 1, the movable contactsegment 4 engages the contact fingers 5, 6 and 10 to complete circuitsand G1. In Fi 9 of to R8, inclusive, and S1,

When the master inclusive,

from the battery B through the coils of the switches R1 and S. Theswitches H1 and S are operated to complete a circuit which may be tracedfrom the trolley conductor 16 through the switch R1, resistors 11 andr2, switch S and the motors 1, 2 and 3 in series to the ground conductor9, as illustrated in Fig. 4 of the drawings.

In position 2 01 the master controller, the switch R1 is released andthe switch R2 is operated to complete a circuit from the trolleyconductor t through the resistor 92 and the motors 1, 2 and 8 in seriesto the ground. conductor 9, as illustrated in Fig. 5 of the drawings. Inposition 3 of the master controller, the switch is operated to place theresistors T1 and T2 in parallel in the motor circuit, as shown in Fig. 5In position 1-. of the master controller, the switch R1 is operated toexclude the resisters T1 and r2 from the motor circuit, as will beunderstood without further illustration.

lVhen the master controller is moved to position 5, which is the firstparallel position of the motors, the switches R1 and R3 are released andthe switches P and (i are operated to complete a circuit which may betraced from the trolley conductor t through the switch F2 and theresistor r, where the circuit divides, one branch extending through theswitch S, motor 1 and the switch G to the grpund conductor 9 and asecond branch extending through the switch F and through the motors 2and 3 in parallel to the ground conductor 9. The circuit thus traced isdisclosed in. Fig. 6 of the drawings. In position. 6 of the mastercontroller, the switch R3 is operated to place the two resistorsfrl andT2 in parallel. in the motor circuit, similarly to the arrangement shownin Fig. 5. In position 7 of themaster controller, which is thefull-parallel position, the switches R1 and R4 are operated to e);-cludethe resistors 71 and r2 from the motor circuit, as illustrated inFig. 7 of the drawings.

The system disclosed in Figs. 8 to 19, inclusive,.may be operatedthrough five series and five parallel positions by the controllercontained therein, as follows: When the master controller is moved toposition 1, the contact segment 17 engages contact [ingers 18, 19 and 23to complete circuits from the battery I31 through the coils oi theswitches R5 and S1. The switches B5 and $1 are operated to complete acircuit through the motors 14, 15 and 16 which may be traced from thetrolley conductor 61 through the switch R5, resistors r3, M and r5,switch S1 and the motors 14, 15 and 16 in series to the groundconductor'gl, as illustrated in F ig.. 11 oi: the drawings. In position2 of the master controller, the switch R5 is released and the switch R6is operated to excludethe resistors T3 and M from the motor circuit, asillustrated in Fig. 12 01' the drawings. In position 3 of the mastercontroller, the switch R7 is operated to place the re sistors T3 and M:in parallel with the resistor T5 in the motor circuit, similarly to thearrangement shown in Fig. 16. In position 1 of the master controller,the switch R7 is released and the switch R8 is operated to ex clude theresistor r3 from the motor circuit and to place the resistors W1 and T5in parallel in the motor circuit, as illustrated in Fig. 13 of thedrawings. In position 5 of the. master controller, which is thefull-series position, the switch. R8 released and switches R5 and R7 areoperated to exclude the resistors r3, "1' 1 and 1 5 from .the motorcircuit, as illustrated in Fig; 1 1 of the:

drawings.

When the master controllerv is moved to position 6, which is the. firstparallel position, the switches R5 and R7 'are released and the switchesP1 and. G1 are operated to complete a circuit in parallel through themotors 1 1 to 16, inclusive, which maybe traced from the trolleyconductor 61 through the switch. R6, resistor r5, where the circuitdivides, one branch extendingthrough. the switch S1, motor 1a and theswitch. G1 to the ground conductor 1 and. the: other branch extendingthrough the switch P1 and the motors 15 and 16 in parallel to the groundconductor 1, as illustrated in Fig. 15 of the drawings. In position 7 ofthe. master controller, the switch R7 is operated to place the resistorsT3 and M: in parallel with the resistor T5 in the motor circuit, asillustrated in Fig. 16 of the drawings. In position 8 of: the master:controller, the switch R7 is released and the switch R8 is operated toexclude the resistor r3 from the motor circuit and to insert theresistors T4; and r5 in parallel therein, as illustrated-in Fig. 17 ofthe drawings. In position 9 of the master controller, the switch R5 isoperated to include the resistor r3 in parallel with resistors W1 and T5in the motorcircuit, as illustrated in Fig. 18 of the drawings, and inposition 10 of the master con troller, which is the full-parallelposition, the switch R7 is operated to exclude the resistors r3, 1 a and1 5 from the'motor circuit, as illustrated in Fig. 19 of the drawings.

In the two systems above described, particular attentionis called to thefact that the three motors, included in either system, are connected inseries across the supply circuit when one switch is operated and thatthe motors may be changed from series to parallel-circuit relation bythe simultaneous. operation of two switches which need notbe interlockedwith any other switches; Fur.- thermore, there is substantially nodecrease in the torque of the motors during the :transi-. tion.Attention is also directed to the-fact that the current is reversedthrough the motor 2 in Fig. 1 and the motor 15 in Fig. 8 of the drawingsduring transition.

In order to simplify the disclosure, no reversing means has beenillustrated in connection with the motors, but it is to be understoodthat any well known means for reversing the motors may be applied to thesystems disclosed.

Various modifications in the circuit connections and the arrangement ofthe controller positions may be efiected within the spirit and scope ofour invention, and we desire, therefore, that only such limitationsshall be imposed as are indicated in the appended claims.

We claim as our invention:

1. In a system of control, the combination with a supply circuit andthree motors initially connected in series-circuit relation thereto, ofmeans for effecting the transition of said motors from series toparallelcircuit relation with substantially no decrease in the torquesupplied thereby.

2. In a system of control, the combination with a supply circuit andthree motors initially connected in series-circuit relation thereto, oftwo switches for effecting a transition of said motors from series toparallel-circuit relation with substantially no decrease in the torquesupplied by said motors.

3. A method of control for a three-motor equipment which consists inconnecting the motor in series-circuit relation, accelerating the motorsin series-circuit relation, effecting a transition of said motors fromseries to parallel-circuit relation while reversing the current flowthrough one of the motors and accelerating the motors while connected inparallel-circuit relation.

4:- In a system of control, the combination with a supply circuit, tworesistors, and three motors initially connected in series through saidresistors to the supply circuit, of a plurality of switches forexcluding said resistors from the motor circuit and for placing saidresistors in parallel in the motor circuit, and means for effecting thetransition of said motors from series to parallel-circuit relation.

5. In a system of control, the combination with a supply circuit, tworesistors and three motors initially connected in series through saidresistors to the supply circuit, of four switches for excluding saidresistors from the motor circuit and for placing the resistors inparallel in the motor circuit, and two switches for effecting thetransition of said motors from series to parallelcircuit relation.

In testimony whereof, we have hereunto subscribed our names this 14thday of July,

ANDREW H. CANDEE. HARVEY H. JOHNSTON.

